*newbie* SHA1 hash computation

I'm completely new to Python and can't wrap my head around this... I'm currently taking a class on this in post-grad school.

Okay, so here's what I need to do.

"Write a Python program that computes SHA1 hashes of a file, but truncates the digest to 8 bits (i.e., throw out all the digest, but the last 8 bits). Use your program to compute the 8-bit SHA1 hash of FILENAME.txt..."

I'm totally lost and would appreciate any guidance...

Thanks in advance.

Mask the hash you compute with 255.

MYHASH & 0xff